ABSTRACT
Objective To observe the effects of Soyasaponins on inflammatory factors, antioxidant activity and exercise ability in rats with severe heat stroke. Methods Eighty male Sprague-Dawley (SD) rats were randomly divided into normal control group, heat shock model group, saline control group and Soyasaponin group, The rats that died during the experiment or with a low rectal temperature (< 41℃) were excluded, and finally 54 rats were included, 18 rats remaining in each group. The rats in the heat shock model group were placed in the simulated hot climate animal cabin at 30 ℃, and the temperature within 30 minutes was raised to 39 ℃ in the cabin with 65% humidity; in the mean time, the rat models of heat shock were replicated under the following situations: let the rats exercise on a treadmill with running speed set at 15 m/min, slope degree 0°, once running for 8 minutes, interval 2 minutes and the heat shock time was 90 minutes, the rats in the normal control group were fed in an environment with temperature ranging from 23-25 ℃ and relative humidity ranging from 50%-70%. After the establishment of models, the saline control group and Soyasaponin group were given daily saline and Soyasaponin (10 mg/kg) respectively by gavage for 3 consecutive months, while the heat shock model group was not given any treatment. The femoral artery blood was collected 24 hours after the rats left the cabin. The serum levels of interleukins (IL-6, IL-1β), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), malonaldehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) were measured by enzyme-linked immunosorbent (ELISA) and the contents of serum hemoglobin (Hb), serum urea (BUN), lactate dehydrogenase (LDH) and blood lactic acid (Lac) were measured by automatie biochemical analyzer. Results The levels of IL-6, IL-1β, TNF-α, IFN-γ, MDA, Hb, BUN, LDH, Lac in heat shock model group were significantly higher than those of the normal control group [IL-6 (ng/L): 86.17±4.82 vs. 12.60±3.49, IL-1β (ng/L): 83.00±5.98 vs. 15.70±3.64, TNF-α (ng/L): 72.22±6.93 vs. 13.75±2.69, IFN-γ (ng/L): 36.22±3.02 vs. 7.35±1.60, MDA (nmol/mg): 19.78±4.56 vs. 6.40±1.35, Hb (g/L): 136.22±1.93 vs. 126.75±5.84, BUN (mmol/L):21.06±3.44 vs. 5.65±1.35, LDH (μmoL·s-1·L-1): 9.65±0.83 vs. 2.12±0.17, Lac (mmol/L): 552.56±78.33 vs. 1.32±0.18, all P ＜ 0.05], SOD and GSH-Px were significantly lower than those in normal control group [SOD (kU/L):97.89±10.57 vs. 126.65±11.35, GSH-Px (kU/L): 19.22±2.58 vs. 43.45±4.02]; however, the levels of IL-6, IL-1β, TNF-α, IFN-γ, MDA, BUN, LDH and Lac in Soyasaponin group were significantly lower than those in heat shock model group [IL-6 (ng/L): 45.28±3.54 vs. 86.17±4.82, IL-1β (ng/L): 41.61±2.93 vs. 83.00±5.98, TNF-α (ng/L):37.22±2.46 vs. 72.22±6.93, IFN-γ (ng/L): 19.22±2.60 vs. 36.22±3.02, MDA (nmol/mg): 11.28±1.74 vs. 19.78±4.56, BUN (mmol/L): 11.78±2.13 vs. 21.06±3.44, LDH (μmoL·s-1·L-1): 3.70±0.26 vs. 9.65±0.83, Lac (mmol/L): 274.56±59.08 vs. 552.56±78.33, all P < 0.01], SOD, GSH-Px and Hb were significantly higher than those of heat shock model group [SOD (kU/L): 116.11±11.28 vs. 97.89±10.57, GSH-Px (kU/L): 31.17±2.90 vs. 19.22±2.58, Hb (g/L): 141.33±3.79 vs. 136.22±1.93, all P < 0.01]; there were no significant statistical differences in above indexes between heat shock model group and saline control group (all P > 0.05). Conclusion After heat shock and exercise management, the production and release of inflammatory factors are increased, and the level of lipid peroxidation was elevated in rats. The Soyasaponin can improve the ability to withstand heat shock and strong exercise by reducing the production and release of inflammatory factors and lipid peroxidation in the rats with severe heatstroke.
ABSTRACT
To explore the effects of different fluid replenishment methods on the internal environment, body thermal regulatory response and severe heatstroke of 5-km armed cross-country training soldiers. Methods A Special Force officers and soldiers who participated in 5-km armed cross-country training (2-3 times a week, 25-30 minutes each time for 3 weeks) during summer training from June to July in 2018 were enrolled, and they were divided into three groups according to the random number table, with 300 trainees in each group. 200 mL of drinking fluids were given to each group 15 minutes before and after each 5-km armed cross-country training: A group with boiled water, B group with purified water, and C group with beverage prepared by pharmaceutical laboratory of the 990th Hospital of PLA Joint Logistics Support Force (100 mL containing 6 g carbohydrates, 42 mg sodium, and 11 mg potassium). The venous blood was collected before and after the last training or during the onset of severe heatstroke to do the following tests: serum cardiac troponin I (cTnI, chemiluminescence), MB isoenzyme of creatine kinase (CK-MB, immunosuppressive), serum creatinine (SCr, enzymatic method), urea nitrogen (BUN, enzymatic method), alanine aminotransferase (ALT, tryptase), aspartate transaminase (AST, tryptase), and Na+, K+, Cl- (electrode method). The heart rate (HR) and core temperature (Tc, anal temperature) were monitored at the same time. The amount of sweat in training and the occurrence of severe heatstroke were also recorded. Results There was no significant difference in heart, liver, kidney function, electrolyte and body heat regulation reaction among three groups of 5-km armed cross-country trainees before training. Compared with before training, the levels of serum cTnI, CK-MB, SCr, BUN, ALT, AST, HR and Tc were significantly increased after training or during the onset of severe heatstroke in three groups, while the contents of Na+, K+, Cl- were significantly decreased, but the increase or decrease of group C was relatively smaller compared with group A and group B [cTnI (μg/L): 0.9 (0.6, 1.4) vs. 1.1 (0.7, 2.8), 1.0 (0.6, 3.3); CK-MB (U/L): 7.0 (5.0, 11.0) vs. 9.0 (6.0, 14.5), 8.0 (6.0, 15.0); SCr (μmol/L): 92.09±18.64 vs. 102.78±18.77, 103.64±20.07; BUN (mmol/L): 7 (6, 9) vs. 9 (8, 11), 10 (8, 13); ALT (U/L): 27 (22, 34) vs. 36 (30, 43), 34 (27, 43); AST (U/L): 37 (31, 48) vs. 41 (34, 50), 39 (34, 51); HR (bpm):87.01±17.07 vs. 95.88±21.06, 96.59±22.04; Tc (℃): 37.73±0.81 vs. 38.03±1.05, 38.10±1.04; Na+ (mmol/L):150.14±3.86 vs. 144.18±8.89, 144.04±9.39; K+ (mmol/L): 4.32±0.57 vs. 4.15±0.62, 4.13±0.51; Cl- (mmol/L):100.43±3.71 vs. 98.42±4.24, 98.41±4.58; all P < 0.01]. The incidence of severe heatstroke in group C was significantly lower than that in group A and group B [1.67% (5/300) vs. 5.00% (15/300), 5.33% (16/300), χ2 = 6.424, P = 0.040]. There was no significant difference in sweating volume in groups A, B, C (g: 370.47±48.71, 370.85±50.66, 370.17±50.21, F = 0.014, P = 0.986). There was no significant difference in the above indexes between group A and group B (all P > 0.05). Bi-classification Logistic regression analysis showed that the increase of HR, Tc and excessive loss of Na+, K+, Cl- were risk factors for severe heatstroke [odds ratio (OR) was 0.848, 0.138, 1.565, 17.996 and 2.328 respectively, all P < 0.01]. Conclusions Timely supplementation of carbohydrate, sodium and potassium ions can effectively change the internal environment and body heat regulation reaction of 5-km armed cross-country trainees, so as to reduce the occurrence of severe heatstroke. The increases of HR, Tc and excessive loss of Na+, K+, Cl- are risk factors for severe heatstroke.
ABSTRACT
Objective To explore the relationship between training burnout, sleep quality and heat regulation response, severe heatstroke in people performed 5-km armed cross-country training. Methods 600 male officers and soldiers who participated in 5-km armed cross-country training in summer from 2017 to 2018 were enrolled. All trainees participated in 5-km armed cross-country training in environment with ambient temperature > 32 ℃ and (or) humidity > 65%. They were divided into two groups according to whether severe heatstroke occurred during 5-km armed cross-country training. The age, military age, body mass index (BMI), physical fitness score, external environment (such as ambient temperature, relative humidity, wind speed, heat index), training burnout score and Pittsburgh sleep quality index scale (PSQI) score, heart rate (HR), core temperature (Tc), sweating volume and serum Na+, K+, Cl- levels were compared between the groups. The risk factors of severe heatstroke during 5-km armed cross-country training were screened by binary multivariate Logistic regression analysis. Results There were 26 cases of severe heatstroke in 600 trainees who participated in 5-km armed cross-country training, with an incidence of 4.33%. There was no significant difference in age, military age, BMI, physical fitness score and external environment of 5-km armed cross-country training between people with or without severe heatstroke. Compared with those without severe heatstroke, the dimensions of training burnout and the total average scores of training burnout of severe heatstroke personnel before 5-km armed cross-country training were increased significantly (physical and mental exhaustion score: 12.4±2.5 vs. 9.4±3.5, training alienation score: 8.8±2.8 vs. 5.8±2.3, low sense of achievement score: 8.2±2.7 vs. 5.6±2.3, total score of training burnout: 9.8±3.2 vs. 6.9±3.2, all P < 0.01), all factors except daytime dysfunction (DD) of PSQI and total PSQI score were also increased significantly [sleep quality (SQ) score: 1.0 (1.0, 2.0) vs. 1.0 (1.0, 1.0), fall asleep time (SL) score: 2.0 (1.0, 3.0) vs. 1.0 (1.0, 1.0), sleep time (SH) score: 1.0 (0.8, 2.0) vs. 1.0 (0, 1.0), sleep efficiency (SE) score: 1.0 (0, 1.0) vs. 0 (0, 0.8), sleep disorder (SD) score: 2.0 (1.0, 3.0) vs. 1.0 (0, 2.0), total PSQI score: 1.0 (1.0, 2.0) vs. 1.0 (0, 1.0), all P < 0.01], HR was increased significantly at onset (bpm: 120.00±10.57 vs. 86.49±14.91, P < 0.01), Tc was increased significantly (℃: 41.46±0.57 vs. 37.97±0.83, P < 0.01), serum electrolyte contents were decreased significantly [Na+ (mmol/L): 130.54±5.97 vs. 143.15±10.56, K+ (mmol/L): 3.72±0.44 vs. 4.37±0.50, Cl- (mmol/L):97.58±4.80 vs. 102.10±2.39, all P < 0.01], and the amount of sweat during training was increased significantly (g: 395.81±16.16 vs. 371.88±40.76, P < 0.01). Binary multivariate Logistic regression analysis showed that total score of training burnout [odd ratio (OR) = 0.653, 95% confidence interval (95%CI) = 0.563-0.757], total PSQI score (OR =0.693, 95%CI = 0.525-0.916), HR (OR = 0.871, 95%CI = 0.838-0.908), Tc (OR = 0.088, 95%CI = 0.043-0.179), sweating volume (OR = 0.988, 95%CI = 0.979-0.997), Na+ (OR = 1.112, 95%CI = 1.069-1.158), K+ (OR = 13.900, 95%CI = 5.343-36.166), Cl- (OR = 1.393, 95%CI = 1.252-1.550) were independent risk factors for severe heatstroke during 5-km armed cross-country training (all P < 0.01). Conclusion Increase in training burnout, total PSQI score, excessive changes of body heat regulation response and excessive loss of Na+, K+, Cl- in serum are independent risk factors for severe heatstroke during 5-km armed cross-country training under the same conditions with high temperature and humidity environment.